JPS6016442B2 - Manufacturing method of modified polyolefin wax - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvement of modified polyolefin wax,
More specifically, a waxy polyolefin having a molecular weight of 400 to 5,000 is treated at 120 to 300 qo under normal pressure or increased pressure in the presence or absence of a catalyst or a reaction initiator.
The maleic anhydride-modified polyolefin wax obtained by reacting with maleic anhydride is treated with 2 to 8 parts by weight of water based on 10 parts by weight of maleic anhydride involved in the reaction at 100 to 180°C under normal pressure or under pressure. The reaction is carried out under pressure, and if necessary, excess water remaining in the system is removed by
The present invention relates to a method for producing a hard and glossy modified polyolefin wax by improving the properties of the modified polyolefin wax by removing it by distillation under normal pressure or reduced pressure.

By controlled polymerization of C2-C4 olefins or mixtures thereof, or by controlled decomposition of their high polymers, waxes with molecular weights of 400-5000 or more are obtained, which are further supplemented with sacrificial,
It is already widely known that useful modified waxes can be obtained by reacting with maleic anhydride to impart reactivity (e.g. British Patent No. 1037405).
[Special Public Sho] 48-41710, etc.).

The method for producing the raw material wax and its modified wax as described above is also described in detail in Tokugan 1977-121000 and Japanese Patent Application No. 1972-121001 filed by the present applicant. The modified wax obtained in this way is
Like many natural waxes and synthetic oxidized waxes, they can be dispersed and emulsified in water or mixed with various oils to make floor polishing emulsions, automobile polishes, etc. by utilizing various properties caused by oxygen-containing polar groups. It is being considered for use as agents, shoe creams, textile and paper treatment agents, inks, coating compositions, etc. The wax used for each of these uses requires specific properties, but generally speaking, these uses often involve coating the surface of objects, so the wax must be hard and non-sticky. In addition, it is necessary to have excellent surface appearance such as gloss and color, and in many cases, it is required to be brittle and easy to crush due to processing needs. Although polymers of C2-C4 olefins or mixtures thereof have the above-mentioned properties to some extent, they are not sufficient, and in particular, as the molecular weight decreases, properties contrary to the above-mentioned required properties appear.
Modifying these polymers with maleic anhydride not only improves various chemical properties associated with the introduction of magnetic groups, but also
Although it has been recognized that the above-mentioned physical properties can also be improved to some extent, the effect is often not sufficient. The inventors of the present invention made an interesting discovery while repeatedly studying modified wax obtained by reacting waxy polyolefin with maleic anhydride while keeping in mind the above-mentioned facts.

In other words, when a modified wax is obtained from a raw material wax with a relatively low molecular weight, it has a soft and sticky feel immediately after synthesis.
It lacks luster and does not meet the requirements of many uses, but if it is left for a long time, it will become hard and brittle.
It also increases the shine.

When we investigated what caused this, we discovered that the cyclic anhydride groups contained in the modified wax gradually released water and opened their rings due to moisture in the atmosphere, and the above changes progressed accordingly. This change itself is generally in a favorable direction, but the rate of moisture absorption is slow, the properties of the wax change over time and stable physical properties cannot be maintained, and the change progresses from the surface to the inside, resulting in a lump of wax. The disadvantages of this modified wax include the fact that the surface and internal properties of the wax are different.

In order to correct this defect and improve the properties required, the present inventors actively added water at the final stage of producing modified wax, and as expected, the result was obtained. It was discovered that the product was hard and brittle from the beginning, had a glossy and smooth surface, and had a bright color.

Furthermore, by varying the amount of water added, we investigated the relationship between the hydrolysis ring-opening rate of the anhydride groups contained in the modified wax and the properties of the wax, and found that favorable changes in properties occurred at a hydrolysis ring-opening rate of 0.1. Initially, generally the water rate is 0.
．． It was discovered that the required properties could be achieved with 5.

Furthermore, it was confirmed that this hydrolyzed acid group was easily dehydrated again by heating, reduced pressure, etc., and it was concluded that the process of removing excess water by distillation after the reaction should be carried out under mild conditions. He discovered this and completed this invention.

The present invention will be explained in more detail below.

The waxy polyolefin used in the present invention is C2-C
The molecular weight is from 400 to 5,000, preferably from 500 to 300, and more preferably from 500 to 1,500. Although the waxy polyolefin can be reacted with maleic anhydride at relatively low temperatures in the presence of a catalyst or reaction initiator, it is generally easily reacted with maleic anhydride even in the absence of these by heating to 180-300°C. The reaction can proceed. Well, below 20 pi, the reaction rate is small,
If the temperature exceeds 300 qo, there is a risk of side reactions such as thermal decomposition, so the preferred temperature range is 220°C to 280 qo. However, since the boiling point of maleic anhydride is approximately 200 q0, pressure-tight sealing is required for the reaction to proceed smoothly. Either by reacting in a container, by adding an excess of maleic anhydride and using conditions such that a sufficient amount is still reacted even if some of it is released, or by adding a suitable hydrocarbon solvent of C81C and refluxing. It is necessary to carry out the reaction while washing back the maleic anhydride that is distilled and sublimed out of the system. The reaction is completed in 2 to 8 hours, but since maleic anhydride generally does not react 100%, it is necessary to remove unreacted components by blowing with N2 or distilling under reduced pressure after the reaction.

The modified wax thus obtained has acidic groups, and the amount can be determined by measuring the saponification value.

The saponification value is a numerical value representing the amount of KOH that reacts with a sample, and can be measured according to ASTM D-1387. Now, if we express the saponification value by P, raw material polyolefin 1
The amount M (evening) of bran water maleic acid that has reacted with each other is M2
1.0 (1) 1,143-1
．． It can be expressed as 0P.

Also, the amount of yen required to hydrate the entire amount of acidic groups in one day of this modified wax (Kite 9) is H = PX hair.
Skin (represented by 2')

Polyolefins and maleic anhydride react with good reproducibility if the reaction conditions are carefully controlled, so as long as the reaction is carried out under known conditions, the saponification value of the resulting modified wax can be predicted with sufficient accuracy for practical use, even without actual measurements. be able to.

The cyclic anhydride group added to the modified wax can be easily hydrated by calculating and adding the required amount of water using the formula '2}, and the enucleation rate can be from 0.1 to 0.1 depending on the application.
An appropriate value between 1.0 and 1.0 can be selected, but if it exceeds 0.5, no clear difference can be observed in the properties of the products, so it is not particularly necessary to set the ring ratio to 0.5 or higher.

However, depending on operational needs, excess water may be added and reacted, and then the excess water may be removed by distillation under appropriate conditions, so this reaction will result in a ring opening rate of 1.0. . In order to react with water, the temperature must be higher than the temperature at which the modified wax has the fluidity necessary for takahai, but if the temperature is too high, the water added will distill out without participating in the reaction, so Within this temperature range, the reaction may be carried out in an open reactor at normal pressure, but it is of course possible to carry out the reaction in a pressure-resistant sealed container.

There is no problem when adding the calculated amount of water, but when adding excess water, it is necessary to remove it by distillation after the reaction, but the acid group opened by water can be easily dehydrated under reduced pressure. Distillation operation should be kept to the minimum necessary, generally 120 to 150 qo, 10 to 10
It is sufficient to distill for 10 to 30 minutes under Hg.

The hydration reaction may be carried out immediately after the maleation reaction and the distillation removal operation of unreacted maleic anhydride, or may be carried out at separate times on the maleated modified wax.

The product thus obtained is harder, more brittle, has a more glossy surface, and has a brighter color than before the hydration reaction.
This makes the wax more suitable for many uses. Comparative example
1 Polyolefin wax, which is an ethylene polymer, was reacted with maleic anhydride to obtain a modified wax.

The properties of the raw wax and the product are shown in Table 1. Table 1 Note [1' Based on everyometry ■ ASTM D1321-70 8' 〃 〃 127-63 ■ 〃 〃 11 spots-59 Compliant side 〃 〃 1387-59 This reaction was performed using raw wax 3.2k9 and maleic anhydride 3
50 qo was placed in the autoclave, and the mixture was allowed to rise to 240 qo under a nitrogen atmosphere, and then stirred at room temperature for 4 hours.

Thereafter, unreacted maleic anhydride was removed at 150:00 at 10 to 2 molar Hg.

Comparative Example 2 The modified wax obtained in Comparative Example 1 was separated and sample '1-
In a drying desiccator, at room temperature, '21, in the atmosphere, 3 pi○
Under temperature, '3' in a container with 100% humidity, at constant temperature of 30℃,
Each sample was allowed to stand still, and the penetration was measured at regular intervals, and the surface layer was scraped off to measure the infrared absorption, and the hydrolysis ring-opening rate of the acidic group was calculated.

Figure 1 shows the change in surface moisture absorption and hardness of the modified wax as the penetration depth and hydration rate over time, and the infrared spectra of the maleic anhydride modified polyethylene wax and the wax with most of its acid groups hydrated. The diagrams are shown in FIGS. 2 and 3, respectively.

In addition, in FIG. 1, the hydration rate of sample {1' was 0 throughout the period, so it was omitted from the graph. Furthermore, in FIG. 2, the pair of absorptions at 1790-1 and 1869-1 are due to the cyclic anhydride group, and the absorption at 1710-1 in FIG. 3 is due to the hydrolyzed ring-opened acid group. As is clear from FIG. 1, the surface layer of modified wax always absorbs moisture, although the rate varies depending on the humidity in the atmosphere, and it becomes harder as it progresses.

It should be noted that sample {1) in a non-moisture-absorbing state also gradually became hard, so it is clear that the hardness is not caused only by moisture absorption, but it is also clear that moisture absorption causes hardness. In addition, once the sample had absorbed moisture, it was placed in a dry atmosphere and left at room temperature for 30 weeks, but no dehydration phenomenon was observed.

In other words, it was found that this wax in which acidic groups were hydrated was sufficiently stable at room temperature, and its properties did not change over time. Example 1 200ml of modified wax made under the same conditions as Comparative Example 1 was put into a flask, heated to 120°C to melt it, and poured 88ml of water while bowing.
The mixture was added dropwise over a period of 30 minutes.

This water is in excess of three times the acidic groups calculated from the saponification value of the modified wax. 120℃ immediately after addition
Excess water was distilled off at 300 mHg. Distillation was completed in 10 minutes. The product exhibited a penetration of 1.5, the surface exhibited good gloss, and the overall color was lighter than the original modified wax.

The modified wax used in Example 1 and the product were rubbed with a metal file, a radish grater, etc.

The original denatured wax became stuck in the rasps, or small pieces fused together, creating a dango-like appearance. However, the product turned into a fine powder. This indicates that the wax became more brittle due to the treatment in Example 1, and that it had properties suitable for crushing treatment.

Example 2 200 g of modified wax made under the same conditions as Comparative Example 1 was put into a flask and heated to melt to 12 g.
．． The mixture was added dropwise over 10 minutes.

50 of the acid anhydride equivalent of the modified wax with 1.5 of water
%. After 15 minutes of washing, a sample of about 20 minutes was taken out for analysis, and an additional 1.4 hours of water was added to the residue.
The reaction was completed after minutes.

The remaining 1.4 liters of water corresponds to the amount required to just hydrate the entire amount of acid anhydride groups remaining. The analysis results of the products of this two-step reaction are as follows. As a result, the hardness of the resulting wax is significantly increased even by partial hydrolysis and ring-opening of acid groups, and in a simple reaction method such as the one used here, some of the water added evaporates and evaporates out of the system. It was found that if it was necessary to increase the reaction rate, reflux or a closed pressure-resistant reaction vessel should be used.

Comparative Example 3 After conducting almost the same reaction as in Example 1, 120
Distillation was carried out under reduced pressure at 5 °C and 5 chest Hg for 1 hour.

When a part of the product was taken out and measured for infrared absorption, it was found that about 30% of the acidic groups were hydrated. After further vacuum distillation at 150° C. and 5 μg for 1 hour, the product contained completely only cyclic anhydride groups. In other words, it has become clear that once hydrated acid groups are easily dehydrated and cyclized under the conditions shown in this example.

Therefore, after carrying out a hydration reaction using excess water, the mildest conditions must be used to remove the water from the hydration reaction by distillation.

[Brief explanation of drawings]

Figure 1 shows the static properties of modified polyolefin wax in a dry desiccator at room temperature (21) in the atmosphere, at 30°C (30°C), and (3) in a container with 100% humidity at a temperature of 30°C. Figures 2 and 3, which are graphs showing penetration and hydration rate versus time, are infrared spectra of a maleic anhydride-modified polyethylene wax and a wax in which most of its acid groups are hydrated, respectively. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A wax obtained by reacting a wax-like polyolefin with a molecular weight of 400 to 5,000 with maleic anhydride at 120 to 300°C, and containing 2 to 80 parts by weight of maleic anhydride involved in the reaction. 100 to 1 part by weight of water
A method for producing a hard and glossy modified polyolefin wax, which is characterized by carrying out the reaction at 80°C. 2. The production method according to item 1, further comprising removing excess water remaining in the system by distillation at 100 to 180° C. at normal pressure or reduced pressure, if necessary.